A ferroelectric capacitor for use in a ferroelectric random access memories (F-RAM) cell is shown in FIG. 1. Referring to FIG. 1 the ferroelectric capacitor 100 typically includes a ferroelectric material 102, such as lead zirconate titanate (PZT) between an upper or top electrode 104 and a lower or bottom electrode 106. The top electrode 104 is electrically coupled to a first contact 108 through a conductive hard-mask layer 110 used in forming the capacitor 100, and the bottom electrode 106 is electrically coupled to a second contact 112 through a conductive oxygen (O2) barrier 114 on a surface of a substrate 116. Generally, sidewalls 118 of the ferroelectric capacitor 100 are encapsulated by a dielectric layer 120 that serves as a barrier to substantially prevent diffusion of hydrogen (H2) into and lead (Pb) diffusing out from the ferroelectric capacitor during subsequent processing steps of the F-RAM, which could detrimentally impact operation of the ferroelectric capacitor.
One problem with conventional ferroelectric capacitors 100 and methods of forming the same is a conductive residue 122 re-deposited on the sidewalls 118 of the ferroelectric capacitor 100 during etching of layers forming the bottom electrode 106 and conductive O2 barrier 114. The conventional approach to removing this conductive residue 122 typically involves one or more complicated dry and/or wet cleans each including one or more steps. These cleans are aggressive potentially damaging other features or elements in the F-RAM integrally formed on a common substrate with the ferroelectric capacitor 100, decreasing a yield of working devices and increasing fabrication time and costs. More fundamentally, as illustrated by the ferroelectric capacitor 100 in FIG. 1, these conventional cleans are not wholly effective in removing the conductive residue 122, leaving some conductive residues on the sidewalls 118 and forming a high leakage path between bottom electrode 106 and top electrode 104 impairing operation of the ferroelectric capacitor 100, or, when the remaining conductive residues are excessive, shorting the bottom electrode and top electrode rendering the ferroelectric capacitor completely inoperative.